There commonly are three levels of fish farming: 1) fish produced exclusively from natural aquatic foods, 2) fish produced by supplementing natural foods with artificial feed, and 3) intensive fish farming under artificial conditions. Besides these, this report discusses also the benefits of fish farming as a source of animal protein and the desirable characteristics of fish for farming such as growth rates, efficient utilization of natural foods, tolerance to water conditions, and disease resistance. In examining present and potential yields through farming selected species of food fish, carp, channel catfish, trout, eels, tilapias, and the polyculture of several species are described. Finally, the technology of utilizing farm-raised fish is reviewed, including domestication of species with desirable consumer or cultural qualities, hybridization, polyculture, computer calculations of least cost rations, hypertensive raceway cultures, reuse of water, and development of new consumer fish products. It seems inevitable that fish farming will increase its contribution to discriminating consumers in both high and low income markets.